This invention relates in general to an apparatus for a motor vehicle for the detection of a full fuel tank. In particular, the apparatus provides a real time confirmation detectable at the fuel fill aperture that the fuel tank has been filled to capacity.
Gasoline powered motor vehicles require the periodic addition of fuel to the fuel tank. When adding gasoline to the vehicle, it is common practice to attempt to fill the fuel tank to its capacity so as to maximize the driving distance that can be achieved before the fuel tank is depleted again. In most instances, an operator adds fuel by one of two methods: (1) standing at the vehicle fuel fill aperture to the fill pipe while manually depressing the trigger of a fuel pump nozzle that has been inserted into the fill pipe so as to allow fuel to flow into the gas tank, or (2) initially inserting the fuel pump nozzle into the fuel fill area, depressing the nozzle trigger, and then using a trigger prop located near the nozzle trigger to place and maintain the trigger in a position so as to allow fuel to flow into the vehicle. Regardless of the method used, in most instances, the fuel pump is automatically shut off at a certain point, indicating to the operator that the pump nozzle should be removed from the fuel fill aperture of the tank and the sale completed.
Although it is advantageous for the fuel pump to stop automatically so as to prevent spillover from the tank, in many cases the operator returns to the driver's seat and starts the vehicle only to observe from a dashboard display that the tank was not completely filled. At that point, after the sale has been completed, most operators consider it too troublesome to get back out of the car to initiate another sale for a relatively small amount of fuel in order to completely fill the tank. Instead, the operator is resigned to his or her fate of driving away from a fuel station without the desired full tank of gasoline. Without an indicator that is both noticeable to the operator positioned near the fuel fill aperture of the vehicle, and functional while the vehicle ignition is turned off, the operator cannot be certain that the fuel tank has been filled to its maximum capacity. Furthermore, if the operator yields to the temptation to top off the tank after the automatic shut-off, there remains the uncertainty as to how much additional fuel should be pumped: too little and the tank remains underutilized, too much and the operator risks exposure to the fuel overspill splash.
A display positioned at the fuel fill aperture was disclosed in U.S. Pat. No. 4,821,697 issued to McDougal on Apr. 18, 1989. McDougal teaches a fuel octane optimization system in which the driver is apprised of the octane requirements for the vehicle by a display. One suggested location for the display is at the fuel fill aperture. However, the system of McDougal does not provide an indication of whether the fuel tank has been completely filled.
A device related to a fluid filling operation was disclosed in U.S. Pat. No. 5, 762,118 issued on Jun. 9, 1998 to Epworth, et al. for an apparatus and method for the remote control of a filling function. Epworth teaches an apparatus and method by which a tank on a mobile vehicle could be filled by remote control. The apparatus includes a control valve, control assembly, and conduit by which an operator at a remote position is able to control the flow of fluid into a reservoir. The apparatus provides a means by which the operator selects a level of reservoir fullness at which the fluid flow would be terminated, so as to prevent wasteful overflow. The Epworth invention does not provide a full tank confirmation at the fill aperture.
There is a need for an apparatus that provides a real-time indication to a motor vehicle operator at the fuel fill aperture that the fuel tank is actually filled to capacity. Such an apparatus would indicate to an operator that more fuel may be added to the tank even though the automatic shut-off of the pump nozzle has stopped the refilling process. The apparatus would facilitate achieving the maximum driving distance between refueling stops, and minimize the operator time spent to engage in the refilling process.
There is a need for a real-time full fuel tank indicator that is functional without requiring the key to be turned in the ignition so that an operator standing outside the car by the fuel fill aperture can determine whether the fuel tank has been filled to its maximum capacity. Returning to the driver's seat to turn the ignition key while the pump nozzle remains engaged in the fill pipe is time-consuming as well as potentially hazardous since there is the risk of unintentionally turning the key to full ignition. Disengaging the pump nozzle eliminates the risk, but also terminates the refueling process and sale. If the driver returns to the driver seat after disengaging the pump nozzle, turns the key, and then observes that the tank has not been filled, adding more fuel would require the driver to repeat the entire refueling process. Despite their disappointment with being unable to obtain a full tank of gas, most drivers would opt to drive away rather spend additional frustrating minutes repeating the refueling process.
There is a need for a full tank indicator that functions in real time and is observable by an operator at the fuel fill aperture so that an operator that desires to add additional fuel to ensure a full tank after the pump is automatically shut off can do so safely. An operator could slowly add fuel until the indicator alerts the operator that the fuel tank is indeed full. At this point the operator could discontinue pumping and avoid overfill splash and spray. Likewise, an operator with a pump nozzle that does not have an automatic shut-off would know at what point the tank has been filled so as to terminate the refilling process safely.